Axis 4,5,6 problem

carmila

hi,

In our company, we have IRB 2400 and IRB 6620. IRB 2400 is supported with conveyor tracking option, and the 6620 supported with flexpendant interface option. For each robot, there are some abnormally event. For IRB 2400, when I use moveAbsJ (0,0,0,0,0) then I run my program (axis 4:0 degree, 5: 90 degree, 6 : -172 degree, linear x= 800mm, y=0mm, z= -500mm), the result is axis 4 become twisted. The position is correct, only axis 4 that has problem.

For the IRB 6620, there are similar problem, when I jog it along axis x, the gripper become tilted (axis 4 rotate), the same case also happened when i jog it along axis z. I already have check the TCP, and the calibration, but it is correct.

Is there any other factors that cause this problem?

thank you so much,

carmila

 

carmila2008-8-28 5:10:17

PerSvensson

Hi
What you see is probally a singularity problem.
Try to use a MoveJ instead of a MoveL from the MoveAbsJ to see if it's a singularity problem.

 

carmila

hi, per!

thanks for your reply. I will change the first moveL to moveJ.

How about our IRB 6620? I don't use the moveL, I only jog it linear, but the gripper is tilted. Is it normal? I've already called the ABB person, but they said this is abnormally. They said it is because of the TCP, but I 've already re-check the TCP using SolidWork software. What should I do?

Thank you

carmila

 

PerSvensson

Same problem there if you try to jog linear.
This isn't abnormal it's normal behaviour that you should consider when programming the robot. There is also instructions like SingAreaWrist that helps you in some way to move thru singularity areas

sanren99999

hi

I known this problem! this because of you  didn't calibrate correctly!you must find the zero position of each axis,and then update revolution counter! Maybe you need do this steps several times,for it's not easy to find the zero position correctly!

carmila

hi per, I will try your advice.

Hi, sanren, thanks for your reply. I will re-update my revolution counter. many times,  i re-update the revolution counter for IRB 2400, I don't know what happened with it, if I unplug the cable (SMB and R1) from the controller, I have to update the revolution counter from the arrival-- June 25-2008 until now, maybe 5 times.

This case didn't happen to IRB 6620. I only make the update in the arrival --july 5 2008.

btw, i will try your solutions, and I will inform you the result I get.

Thank you so much,

carmila

 

carmila2008-8-29 4:21:7

sanren99999

you needn't  to unplug the cable,just update the revolution counter!

jog to the position close to the zero position,then update the revolution counter!

try to do this!

i had met this problem yesterday!

my robot :IRB4400